Analysis and characterization of the X‐ray beam produced by a PF device for radiotherapy applications

Abstract

A plasma focus device, devoted to the study of a possible application to the radiotherapy treatment of malignant cells, has been recently put into operation. The low-energy (up to 200 keV) X-rays are produced by conversion of the electron beam generated by the device during the pinch phase. The X-ray spectrum has already been fully characterized, and an initial campaign of irradiation of specific cell cultures has been completed. At present, the links between the operational parameters of the actual device, the beam intensity, and the cell irradiation effects are being analyzed, trying to evaluate the advantage of the very high dose rate that can be delivered, of the order of several Gy in a few tens of nanoseconds. Preliminary results on radiobiological effectiveness are presented and discussed.

Enhancing radiosensitivity of melanoma cells through very high dose rate pulses released by a plasma focus device

“…Among those, a naturally collimated electron beam is driven to collide with a target to produce X-Rays. This electron bunch is very intense (0.1 mC) with 10 15 electrons produced [ 13 ]. It is this fast and impressive production that makes the difference, in terms of DR, with other technologies.…”

“…Moreover, PFMA-3 manufacturing, utilization and radiation protection arrangements require quite low costs in contrast to the high application flexibility ( Table 2 ). Preliminary data about antitumor efficacy of PFMA-3 have been obtained in glioblastoma (T98G cell line) [ 12 ] and breast cancer preclinical models (MCF-7 cell line) [ 13 ]. Although the effects of an important DR variation after low-LET radiation has been reported for several years [ 55 ], up to now limited recent biological data have been published on very high DR effect in tumor.…”

Dose-current discharge correlation analysis in a Mather type Plasma Focus device for medical applications

“…In the past, some efforts have been put in finding a way to predict the neutron yield from D-D or D-T fusion reactions coming from a PF pinch by considering its constructional and operational parameters, like the capacitor's bank energy, the chamber pressure and the operating voltage (Patran, 2005). Recently, the PF technology has been proposed as a viable fast X-ray source: the electron beam emitted from inside the pinch can be used to produce X-rays via the interaction with a suitable target (Tartari (2004), Ceccolini (2012); Sumini (2015)). The main unsolved issue with this technology is that, under very similar operating conditions, the radiation yield and spectrum can vary at every discharge: this is particularly true for the spectrum of the electrons emitted from the pinch.…”

X-ray photons produced from a plasma-cathode electron beam for radiation biology applications

“…Low-energy and high intensity X-ray sources can also be produced either in direct laser-plasma interaction 18 or with plasma focus devices 19 . With X-ray fluxes up to several 10 10 photons.sr −1 .s −1 and small spot area of 100 µm 2 , X-ray sources based on direct laser-plasma interactions open new perspectives in medical imaging 18 .…”

“…A similar number of Xray photons can be emitted from a large-spot plasma focus devices in a single shot. They can deliver dose rates of several Gy in a few tens of ns in cells, allowing applications in radiotherapy 19 . However, the dose rate produced by all these devices cannot be easily adjusted over a wide range, thereby limiting in vivo experiments with biological models.…”